1. Field of the Invention
The invention relates generally to socket tools of the type used for socket wrenches and the like and, more particularly, to socket tools of the type which are designed for use in environments which are corrosive or present a spark or shock hazard.
2. Description of the Prior Art
Conventionally, socket tools, such as for socket wrenches and the like, have been made of a suitable metal, such as iron or steel, to afford the necessary strength and durability. Such metal socket tools are manufactured using machining and/or casting or forging techniques. An important disadvantage of metal socket tools is their cost, from both manufacturing and material standpoints. Moreover, metal tools are unsuitable for use in many applications, particularly when a shock or spark condition exists, or when the exterior of the tool is exposed to highly corrosive or magnetic environments. Furthermore, metallic socket tools can tend to mar associated structures with which they come in contact in use.
Insulated socket tools have been provided which afford an insulating covering on the outside of the metal socket tool, which covering may be formed of a suitable plastic or other electrically insulating material. This insulating coating or layer can be easily damaged or may be deteriorated to a point when the insulating and non-sparking properties of the tool are severely compromised and pose a threat to the safety of the user. Also, the insulated tools may still not be suitable for use in certain magnetic environments.
The present invention is an improvement of the socket tool disclosed in copending U.S. application Ser. No. 462,804, filed Jun. 5, 1995, and entitled "Composite Socket Tool" (now abandoned). That socket tool has a tool body which is formed of a glass fiber-reinforced composite plastic material which is non-metallic and, therefore, non-magnetic, non-conductive and non-sparking, and is also lighter in weight and cheaper than a comparably-sized metal socket tool, while being corrosion resistant and non-marring. In order to better bear the high contact stresses of the drive stud of an associated driver tool, the driven or input end of the socket tool is provided with a metal square drive insert which is insert-molded in the socket tool body. It has been found in use that, in certain applications, the output or driving end of the socket tool is also subjected to high contact stresses with associated fasteners and the like, which may unduly strain or deform the driving end of the socket tool.